Improved buying and burning-kiln



LBUHRBR. DRYING AND BURNING KILN.

N0.482,488. Patented Sept. 29,1868.

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JACOB Bunsen, O-F-YMUNIICH, BAVARIA.

Letters Patent No. 82,488, dated September 29,- 1868; patented in England, February 28,1867.

IMPROVED DRYING AND BlIBNIKG-KILN.

510 ALL WHOM IT MAY CONCERN:

Be it known that I, JAOOB B i'IHRER, of Munich, in the Kingdom of Bavaria, have invented or discovered certain new and useful Improvements in Ovens or Kilns for Drying and Burning'Bricks and other Articles and I do hereby declare that the following is a full, true, and.exact description thereof, reference being bad to the drawings hereunto annexed; that is to say- I The chief object of this invention is to construct ovens and kilns for carrying one particular mode of efi'ecting the combustion of the fuel; and in order that this object may be fully understood, I will first describe the mode in which the combustion of the fuel is eflected, although this mode forms the subject of a separate patent, already granted to me in the United States.

The fuel whichI employ, consists of coal, anthracite, coke, shale, peat, or other like matter, in as fine a i state of division as his practicable to obtain it. This fuel, in a state of powder or dust, is allowed to fall through a suitable orifice, in such a way that thejiiow o'i' the'powd'efc'afifble regulated," tuttia. space'inithe weaver.kiln,

where it meets airprey-iously heated, and whilst in the act of falling-it takes fire, and is consumed whilst suspended in the air, thereby undergoing the most perfect combustion. This mode of applying the fuel resem-- bles in fact the burning of gas, with this difference, that the gas is generated, in this instance, at or near the placewhere it is-to be burnt. A draught carrying the burning particles of fuel along into thespaces left between-the briclis or other articles, 'a perfect and uniform heat is obtained, which can be regulated-with great facility, and which insures the bricks or other articles to be burned receiving a uniform temperature throughout and in every part of the kiln, which is an object of the greatest importance, not previously obtained by any other means or contrivance. t

For the purpose of eco'nomizing the heat given of in the process of burning, I make use of' a kilnof a.

peculiar construction, which, whilst it admits a continuous process of'burning, issoarranged as to' allow part of the heat retained in the burnt articles to be drawn away along with the gaseous products of the combustion, by means of a ventilator, or fan, or chimney, through a series of drying-chambers, in which the bricks are thus economically dried to such a degree that they are almost absolutely free from water previous to their being put into the kiln. From the description of the ovens and kilns hereafter given, it will be perceived that by' their mode of working, nearly the whole amount of heat generated'by the fuel is-utilized and in the case where p a fan is used, it has been fou'nd'that the moist air which issues from the fan is only about from 60 to 75 .Falirenheit higher than the ordinary temperature of theatmosphere. I I i I Inow proceed to describe the'construction and operation of the ovens and kilns.

Now follows the description of kiln and drying-chamber, then the mode ofworking the some from the,"

commencement.

My invention, in so far as it relates to ovens for drying bricks and other articles, consists in constructing them in a series of oblong rectangular compartments, placed s ide by side in two rows, the'two rows being set' back to hack; in connecting each compartment with those next adjoining. by'openings in the dividing-walls,

and in the arrangement of dues, doors, and dampers, as hereafter described, wherebyI am enabled to regulate the supply of heat to the compartments, for the purpose of. carrying on a particular process of drying, as hereafter explained. I

My invention, in so far as it relates to kilns, consists in constructing them, in a similar manner to the ovens, of a series of oblong rectangular compartments, built side by side in two rows set back to back. The compartments communicate with each other like those of the oven, and there are fines, doors, and dampers to enable them to be worked in a similar manner to those of the oven. As the thrust resulting from the expansion of the brick-work will only be towards the ends of the rows, these end walls areconstrueted of the necessary thickness, with supporting piers, whilet-he intermediate walls may he comparatively thin. According to this -construction there will be little exposure to the air, and therefore little loss of heat, and a great economy in brickwork will be effected- My invention Ill be fully understood by the annexed drawings, and the following description thereof. Figure 1 is a general-plan or view of the system of drying and burning combined. Figures 2 and 3 are sections, through F K and G H respectively, of fig. 8. Flgul": 4 is an elevation of the end A B of fig. 8. Figure 5 an elevation of the side B E of fig. 8. Figures 6 and 7 are sections respectively, through the lines L M and G D, of fig. 8 and Figure 8 is a plan of the drying-oven and kiln combined. This figure is in'section except at the parts marked S T and B, Q.

I will first describe the drying-oven. It consists, as before mentioned, and as seen in the drawings, of a series of oblong rectangular compartments, set side by side in two rows, whichare set back to back. I have I shown twenty-four compartment-s, but any otheroonvenient number may be employed. The side walls of each compartment have openings k, alternately at back and front, as shown, communicating with the next adjoining compartments, and the end compartments of ope row communicate with the end compartments of the other row, by openings 71. in the middle wall These openings h are thus so arranged, that were they all unclosed, there would be a zigzag passage for a current through thecompartments in one row, which would be continued by a zigzag passage in the opposite direction through the compartments in the other row. -The openings hare,

however, provided with doors or dampers, as represented at no, fig. 8, which can be opened and closed, as required,

as the drying-process is being carried on. Under the middle wall, (see fig. 6,) tw0 fiues are formed, one marked 6 for. the heated air for drying the bricks, and the other marked a for carrying off the air after leaving the bricks. Two similar flues are formed under each of the two outer side walls of the ovens, viz, a flue, c, for heated air, and one, d, for escape air-under the wall to the left of fig. 2, and a fine, e, for heated air, and one, f, forescape airin the wall to the right of fig. 2. These fiues communicate with the various compartments, that is to say, every compartment is in communication with one heated-air flue and with one escape-air flue. This arrangement or system will be understood by fig. 8, in which m are the communications with the escape-air fines, and n the communication with the heated-air flues. The escape-air fines are colored green and the heated-air flues red. The communications m and n are each provided with a door or damper, opened and closed as the progress ofthe drying-process requires. V is a ventilator or fan, for exhausting the air from the escape-air flues, and P is a furnace for heating and assisting the draught through the heated-air fiues, with which it is in communication by short fines, as indicated in fig. 8. The heated air and draught are, however, chiefly derived from the kiln, I

which is in communication, at the point Z, fig. 8, with the heated-air fines b, c, and e. Each compartment has an opening, 9, at the front, provided with a door or damper.

The process of drying In. this oven constructed with flues, as before describedggis carried on as follows, and will'be understood on reference to fig. 1.

l I divide the compartments into, say, sets of five. No. 1 of each set will be in course of being emptied and refilled through the door at its front; No. 2 will be cooling by means of air admittedthrough No. 1; No. 3 will contain nearly dry bricks; No. 4 half-dried bricks, and No. 5'green or wet bricks. The necessary dampers and doors are open to allow the hot air from the kiln to enter No. 3 of each set, to pass from thence at a diminished heat to No. 4, and then at a still .less heat to No. 5, from which it issues by one of the escape-fines.

After a certain time the bricks in No. 3 will be quite dry, those in No. 4 nearly dry, and those in No. 5 half dried,while No. 1 willhave received fresh green bricks, and the bricks in No. 2 will be sufficiently cooled for' removal. I then closeand open the necessary dampers and dborsto make No. 4 of each set No. 3, or the coinpartments which first receive the hot air; No. 5 will thus become No. 4; No. 1 of the set in front will become No. 5 of the first set; No. 3 of the first set will become No. 2; No. 2 will become No. 1, and No.1 will become .No. 5 of the set behind. The operation is thus carried on continuously through the whole series of compartments of theoven. The red arrows in fig. 1 show the direction or course of the hot air, and the green arrows that of the escape air.

I now proceed to describe the kiln to the compartments of which the bricks are removed after being dried in the oven. The kiln shown has twelve compartments, which I consider a convenient number. There is one central fine with which every alternate compartment communicates, through openings 0, provided with dampers. The compartments communicate with each other by openings e in the dividing-walls, and every alternate opening e is provided with a door or damper, actuated from the top, as indicated by 6, fig. 8. It will thus be understood that-these compartments are arranged, as it were, in pairs. The several pairs are worked progressively and continuously in an analogous manner to that before indicated in reference to the oven. Each compartment is provided'with an opening-cl, at the front, fitted with a door or damper. The compartments are fed with fuel from the top, through apertures a. This fuel is in the state of fine division, and as it falls through the bricks, the combustion is efi'ccted by the great heat of the bricks themselves, which have previously been heated by the products of combustion from the compartments behind. On reference to fig. 1, it will be seen that the doors at the front of compartments 1 and 2 are open, and that fuel is being fed to 8. 3, 4, 5, 6, and 7 have previously been burnt, and 8, which is now being fed, has been made so hot by the products from behind, that the powdered fuel supplied to it is at once consumed. No. 1 is being emptiedand refilled, cold air is rushing through No. 2 to cool the bricks therein, and after passing through 3, 4, 5, and 6, a portion of it issues in a heated state through theapertures c of 6, into the flue below to go to the oven, while the remainder proceeds through 7 to 8 to sup ort the combustion therein. The mode of drawing the cold air through the hot bricks in 3, 4, 5, and G, and throught he aperture 0, direct to the drying-compartments, affords great advantages. The

heat and products of combustion from 8,'pass through 9, 10, ll, 12, and heat or partially burn the bricks therein,

and finally issue in a heated state, by the aperture 0 of 12, into the flue below leading to the oven.

W'hen the bricks in No. 8 Me sufiiciently burnt, the necessary door and dampers are closed and opened to .admit of the same process being carried on from No. 9, which is then supplied with fuel, the door of No. 3 is opened to admit cold air, and the damper in 8 is opened to' allow a portion of this air, after being heated, while passing through 4, 5, 6, 7, and 8, to issue into the central flue. The same process is carried on continuously and progressively through the series of compartments. In burning pottery and other articles, when it will be injurious to allow the fuel to come in contact'therewith, a space may be left unfilled in each compartment of the kiln, into which space the fuel is dropped, and consumed in manner before explained. a 6 (see fig. 7,) is a flue or channel above the compartments, to allow of air enteringit, and passing, after being heated, into the fines of the oven. The top of the kiln is filled in with clay or other suitable material, to prevent loss of heat as much as possible. It will be observed that very little surfaceot' each compartmentis exposed to the outer'air, that the inner walls can be comparatively thin, owing tothe arrangement of the compartments, and that the two end walls are of the necessary thickness to resist the force of expansion exerted" by the heat. The end wall further from the oven is supported by piers, as seen in fig. 4, while the further end of the oven is similarly supported. U is a chimney, communicating by a flue with the kiln. This chimney may be employed for producing draught when a ventilator is not used.

I do not claim, as my present invention, the particular mode of efl'ecting the combustion of the fuel in a state of fine powder, because, as before stated, this forms the subject of prior Letters Patent; neither do I claim the progressive and continuous manner of drying the bricks, or of burnin'g the bricks when dried, as this process is very old. In 1841, one Joseph Gibbs obtained Letters Patent, for England, fora kiln constructed in a. circular or annular form, divided into a series of compartments, with flues leading toone central chimney, and the pr oeess of burning was progressive and continuous, as in my. kiln and oven. In fact the old common mode of burning bricks in stacks in the open air is progressive, because, as the fire is lighted at the bottom, the lowest layer of bricks is-burnt first, the fuel above them then becomes ignited, and burns the next layer of bricks and soon progressively to the top. I do not, therefore, I say, claim the mode of burning or drying bribks in a progressive or continuous manner; but

' What I claim as my invention, and desire to secure by Letters Patent, is

A drying-kiln, as shown, consisting of a series of compartments placed back to back in a double row, and

provided with the openings g, hot-air supply and escape flues a, b, c, d, e, andf, and communicating aperturesm and n, in combination with a burning-oven, also consisting of a number of compartments similarly disposed to those of the kiln, and provided with the openings d'and e a, all the parts being constructed and arranged as and for the purposes herein set forth. r

In witness whereof, I, the said JACOB BiiHRER, have hereunto set my hand, this 4th day of November, 1867.

JACOB BUHRER. Witnesses:

S. Snrz,

-I'I. SALATHE',

}Basle, Switzerland. 

